Nonequilibrium Josephson and Andreev current through interacting quantum dots

Abstract

We present a theory of transport through interacting quantum dots coupled to normal and superconducting leads in the limit of weak tunnel coupling. A Josephson current between two superconducting leads, carried by first-order tunnel processes, can be established by the nonequilibrium proximity effect. Both the Andreev and the Josephson currents are suppressed for bias voltages below a threshold set by the Coulomb charging energy. A π-transition of the supercurrent can be driven by tuning gate or bias voltages. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.